Limb mounting system for archery bow

ABSTRACT

An archery bow includes a bow riser, a limb, a limb bolt and a pivot pin. The bow riser is formed at one end with a rearward portion that includes a cradle and a bridge spanning the cradle to form a passageway therebetween and a tunnel defined in an inner wall of the bridge. The limb bolt attaches a butt end of the limb to a forward portion of the bow riser. The pivot pin passes through the passageway in the rearward portion of the bow riser and positioned in the cradle of the rearward portion of the bow riser. Moreover, the pivot pin defines in a top a pair of recesses in which two limb members of the limb are nested respectively, and is formed on a bottom a pair of positioning studs together clasping opposite ends of the cradle of the rearward portion of the bow riser.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to archery bows. More particularly, this invention relates to an apparatus for mounting a bow limb to a bow riser.

2. Description of the Related Art

Nowadays there exist a various of ways for mounting the upper and lower bow limbs to the ends of a bow riser of a compound archery bow. Most commonly, the butt of each bow limb is positioned in a rectilinear limb pocket aligned contiguous with the outer planar surface of the bow riser. The limb butt is then affixed to the riser by a limb bolt inserted through a hole in the limb butt, through a corresponding hole in the limb pocket and then threaded in a threaded hole in the forward most end of the outer planar surface of the riser. Besides, one may further employ a vibration damping cup or pad in the limb pocket, as disclosed in the U.S. Pat. No. 7,308,890, to reduce undue noise which could be caused by the recoil vibration occurring as the arrow is released from the bow.

Different from the bow using the limb pocket, another type of an archery bow 900 is illustrated in FIG. 8, which includes a limb bolt 91 and a fulcrum 92 offset from the limb bolt 91 along a length of a bow limb 90. During drawing of the bow, the bow limb 90 pivots against the fulcrum 92 on the rearward edge of the riser 93. The draw weight of the bow 900 may be slightly reduced by unthreading the limb bolt 91 a slight distance to decrease the distance between the tips of the upper and lower bow limbs 90. As shown in FIG. 9, however, the fulcrum 92 is made up of components such as an axle 921, a pair of supporting blocks 922, 923, two bolts 924, 925 and two vibration damping pads 926, 927. The axle 921 is positioned on the rearward edge of the riser 93. The two bolts 924, 925 attaches the two supporting blocks 922, 923 to the opposite ends of the axle 921. The two supporting blocks 922, 923 are provided to hold the limb 90 and each is capable of pivoting slightly about the axle 921 in order to reduce stress on the rearward edge of the riser 93 during drawing of the bow. Each of the vibration damping pads 926, 927 are sandwiched between the rearward edge of the riser 93 and a limb member of the limb 90 in order to reduce vibration and noise during drawing of the bow.

As described above, it is clear that no matter it is the limb pocket or the second type of the limb mounting system, a lot of components are needed simply for mounting the limb on the riser, which would have to be specially manufactured thereby increasing the cost of the archery bow even further.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an improved archery bow, in which the limb mounting system can generate relatively less vibration and noise during drawing of the bow and be produced at relatively less cost.

The foregoing and other objects and advantages are attained, according to the present invention, by an archery bow comprising a bow riser, a limb, a limb bolt and a pivot pin. The bow riser is formed at one end with a forward portion and a rearward portion. The rearward portion includes a cradle and a substantially arched-shaped bridge spanning the cradle to form a passageway therebetween and a tunnel defined in an inner wall of the bridge and adjacent to the passageway. The limb has a pair of limb members generally parallel to each other. The limb bolt attaches a butt end of the limb to the forward portion of the bow riser.

In particular, the pivot pin extends through the passageway in the rearward portion of the bow riser and is positioned in the cradle of the rearward portion of the bow riser. Moreover, the pivot pin defines in an upper surface thereof a pair of recesses in which the two limb members of the limb are nested respectively, and is formed on a lower surface thereof a pair of positioning studs together clasping opposite ends of the cradle of the rearward portion of the bow riser. The positioning studs of the pivot pin are configured in shape and size to be able to pass through the tunnel in the inner wall of the bridge during assembly.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an archery bow in accordance with a first embodiment of the present invention;

FIG. 2 is a partially exploded perspective view of the archery bow shown in FIG. 1;

FIG. 3 is a partially enlarged view of the archery bow shown in FIG. 2;

FIG. 4 is a cross-sectional view of the archery bow taken along the line IV-IV shown in FIG. 1;

FIGS. 5 and 6 are partially enlarged side views of the archery bow shown in FIG. 1, showing the process of mounting the limb on to the bow riser;

FIG. 7 is a partially exploded perspective view of an archery bow in accordance with a second embodiment of the present invention;

FIG. 8 is a partial perspective view of a conventional archery bow; and

FIG. 9 is a partially exploded perspective view of the conventional archery bow shown in FIG. 8.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring now in detail to the drawing, there is shown an archery bow indicated generally at 100. As shown in FIGS. 1 and 2, the archery bow 100 includes a metallic bow riser 1, two limbs 2, 3 and two limb mounting systems for mounting the limbs 2, 3 onto upper and lower ends of the bow riser 1. Each limb mounting system includes a limb bolt 4, a pivot pin 5 and a limb cap 6. Since the lower limb 3 is of the same design as the upper limb 2, except that it is the mirror image with respect to the left and right plan aspects; accordingly, the following description of the upper limb 2 along with the related limb mounting system and views of FIGS. 3-6 are applicable to the lower limb 3, except for top to bottom reversal.

As best seen in FIG. 3, the bow riser 1 is formed at its upper end with a forward portion 11 and a rearward portion 12. The rearward portion 12 includes a cradle 121 and a substantially arched-shaped bridge 122 spanning the cradle 121 to form a passageway 124 therebetween and a tunnel 123 defined in an inner wall of the bridge 122 and adjacent to the passageway 124. In this case, the bridge 122 is partially crumpled to form the tunnel 123, as depicted in FIG. 5 or 6, which is provided for passing of a positioning stud 52 of the pivot pin 5, as will be discussed in detail later.

Referring to FIGS. 1 and 3, the limb 2 is mounted to the upper end of the bow riser 1 and includes a pair of limb members 21, 22 substantially parallel to each other. In this embodiment, the two limb members 21, 22 are separately made from glass fiber or graphite fiber and has no intersection at all. The limb bolt 4 extends through the hole 60 in the limb cap 6 to attach a butt end of the limb 2 to the forward portion 11 of the bow riser 1. The limb cap 6 is positioned between the limb bolt 4 and the butt end of the limb 2 and covers the front ends of the limb members 21, 22 to retain the butt end of the limb 2 from lateral movement. The draw weight of the bow 100 may be slightly adjusted by means of the limb bolt 4.

Referring again to FIG. 3, the pivot pin 5 extends through the passageway 124 in the rearward portion 12 of the bow riser 1 and is positioned in the cradle 121 of the rearward portion 12 of the bow riser 1. Thus, the pivot pin 5 is allowed to be slightly rotate, which permits the limb 2 to slightly move to reduce the stress imparted to the limb 2 that pivots against the pivot pin 5 during drawing of the bow.

More specifically, the pivot pin 5 defines in its upper surface a pair of recesses 51 in which the two limb members 21, 22 of the limb 2 are nested and confined respectively. The pivot pin 5 is further formed on its lower surface a pair of positioning studs 52 together clasping opposite ends of the cradle 121 of the rearward portion 12 of the bow riser 1 and thereby is tightly attached onto the riser 1. Preferably, the pivot pin 1 is made of plastic, such as nylon and therefore further serves as a damping member to reduce undue noise caused by the recoil vibration as the arrow is released from the bow. When compared with the prior art bow, this configuration is beneficial in that no extra damping cup or pad will be needed.

It is noted that the positioning studs 52 of the pivot pin 5 are configured in shape and size to be able to pass through the tunnel 123 in the inner wall of the bridge 122. Specifically, as shown in FIG. 5, during the assembly process, the pivot pin 5 is turned to have the positioning studs 52 directed upward to be aligned with the tunnel 123 in the bridge 122. Then, the pivot pin 5 is inserted into the passageway 124 between the cradle 121 and the bridge 122 to a predetermined position. At this time, one of the positioning studs 52 of the pivot pin 5 has passed through the tunnel 123 in the bridge 122. Finally, the pivot pin 5 is rotated as indicated by the arrow to have the positioning studs 52 face down and lock the cradle 121 therebetween, as illustrated in FIG. 4.

Referring now to FIG. 7, there is shown an alternate embodiment 200. Embodiment 200 is similar to embodiment 100, except that an integral molded limb 2 a is provided in lieu of the aforementioned limb 2 having the two separated limb members 21 a, 22 a. The plastic limb 2 a is formed in one piece with two substantially parallel limb members 21 a, 22 a connected at the butt end thereof, as can be seen in FIG. 7. This configuration is beneficial in that no limb cup will be needed since they are confined by each other.

It is to be understood that the disclosed embodiments are illustrative in nature and the invention is not to be limited to any one or more embodiments except as set forth in the following claims. 

What is claimed is:
 1. An archery bow comprising: a bow riser formed at one end with a forward portion and a rearward portion; the rearward portion including a cradle and a substantially arched-shaped bridge spanning the cradle to form a passageway therebetween and a tunnel defined in an inner wall of the bridge and adjacent to the passageway; a limb having a pair of limb members generally parallel to each other; a limb bolt attaching a butt end of the limb to the forward portion of the bow riser; and a pivot pin passing through the passageway in the rearward portion of the bow riser and positioned in the cradle of the rearward portion of the bow riser; the pivot pin defining in an upper surface thereof a pair of recesses in which the two limb members of the limb are nested respectively, and being formed on a lower surface thereof a pair of positioning studs together clasping opposite ends of the cradle of the rearward portion of the bow riser; and the positioning studs of the pivot pin being configured in shape and size to be able to pass through the tunnel in the inner wall of the bridge during assembly.
 2. An archery bow as recited in claim 1, wherein the pivot pin is made of plastic.
 3. An archery bow as recited in claim 2, wherein the pivot pin is made of nylon.
 4. An archery bow as recited in claim 1, wherein the limb is integrally formed in once piece with the two limb members of the limb connected at the butt end thereof.
 5. An archery bow as recited in claim 1, further comprising a limb cap positioned between the limb bolt and the butt end of the limb.
 6. An archery bow as recited in claim 5, wherein the two limb members of the limb are made of glass fiber.
 7. A limb mounting system for mounting a limb to a bow riser, wherein the limb has a pair of limb members; the bow riser is formed at one end with a rearward portion; the rearward portion including a cradle and a substantially arch-shaped bridge spanning the cradle to form a passageway therebetween and a tunnel defined in an inner wall of the bridge and adjacent to the passageway; the limb mounting system comprising: a pivot pin passing through the passageway in the rearward portion of the riser and positioned in the cradle of the rearward portion of the riser; the pivot pin defining in an upper surface thereof a pair of recesses in which the two limb members of the limb are nested respectively, and being formed on a lower surface thereof a pair of positioning studs together clasping opposite ends of the cradle of the rearward portion of the riser; and the positioning studs of the pivot pin being configured in shape and size to be able to pass through the tunnel in the inner wall of the bridge during assembly.
 8. A limb mounting system as recited in claim 7, wherein the pivot pin is made of plastic.
 9. A limb mounting system as recited in claim 7, further comprising a limb bolt attaching a butt end of the limb to the riser.
 10. A limb mounting system as recited in claim 9, further comprising a limb cap positioned between the limb bolt and the butt end of the limb. 